Foldable ladder

ABSTRACT

A step ladder structure having a foldable tripod supporting frame. The ladder component utilizes substantially parallel side pieces with connecting steps and with one of the legs of the tripod frame serving as one of the ladder side pieces. The other side piece has an upper and lower section hingedly attached in longitudinal alignment so that the lower section is capable of a slight misalignment with the upper section. The lower section is normally capable of engaging a level support surface to serve as a support leg when weight forces are on any step attached thereto and on a slightly unlevel surface, the hinged construction permits the lower section to also engage such support surface as a support leg when weight is concentrated on any steps connected to such section. However, this is merely a matter of convenience when mounting on and dismounting from the ladder for if there is no ground engagement by such lower section, the stability of the ladder is not affected since appropriate brace structure is operatively associated with the tripod frame to assure that weight forces on any step of the ladder are appropriately distributed to the tripod frame and when weight forces are on any step not connected to the lower section, such section is not required to and does not function as a support leg irrespective of whether it may be in contact with the ground support. This ladder includes adjustable brace structure for securely holding it in selective positions of partially extended position so that it may be utilized in confined areas. This ladder also includes a removable standard to steady a person standing on the top plate and such standard may be employed to contain an umbrella as a shield from the sun. A removable seat and a removable foot rest are provided relative to the top plate for the convenience of the user under different circumstances. Detachable bearing feet are provided to make the ladder usable efficiently in soft or muddy ground and to also maintain the ladder component in an appropriate vertical plane when the ladder may be used on uneven or unlevel ground.

United States Patent Emmons 51 Jan. 25, 1972 [54} F OLDABLE LADDER [72] inventor: George Harvey Emmons, l 1 South 12th St., Marshalltown, Iowa 50158 [22] Filed: July 23, 1970 [2]] Appl. No.: 57,484

Related US. Application Data [63] Continuation-impart of Ser. No. 847,099, Aug. 4,

1969, Pat. No. 3,540,549.

[52] U.S.Cl ..182/170,182/108,182/120; 182/129 [51] Int. Cl. ..E06c U383 [58] Field of Search ..l82/170, 173, 175, 176, 108, 182/120, 129

[56] References Cited UNITED STATES PATENTS 281,977 7/1883 Coons ..l82/l70 Primary Examiner-Reinaldo P. Machado Attorney-Morton S. Adler 1571 ABSTRACT A step ladder structure having a foldable tripod supporting frame. The ladder component utilizes substantially parallel side pieces with connecting steps and with one of the legs of the tripod frame serving as one of the ladder side pieces. The f,

other side piece has an upper and lower section hingedly attached in longitudinal alignment so that the lower section is capable of a slight misalignment with the upper section. The lower section is normally capable of engaging a level support surface to serve as a support leg when weight forces are on any step attached thereto and on a slightly unlevel surface, the hinged construction permits the lower section to also engage such support surface as a support leg when weight is concentrated on any steps connected to such section. However, this is merely a matter of convenience when mounting on and dismounting from the ladder for itthere is no ground engagement by such lower section, the stability ofthe ladder is not ai fected since appropriate brace structure is operatively associated with the tripod frame to assure that weight forces on any step of the ladder are appropriately distributed to the tripod frame and when weight forces are on any step not connected to the lower section, such section is not required to and does not function as a support leg irrespective of whether it may be in contact with the ground support. This ladder includes adjustable brace structure for securely holding it in selective positions of partially extended position so that it may be utilized in confined areas. This ladder also includes a removable standard to steady a person standing on the top plate and such standard may be employed to contain an umbrella as a shield from the sun. A removable seat and a removable foot rest are provided relative to the top plate for the convenience of the user under different circumstances. Detachable bearing feet are provided to make the ladder usable efficiently in soft or muddy ground and to also maintain the ladder component in an appropriate vertical plane when the ladder may be used on uneven or unlevel ground.

17 Claims, 13 Drawing Figures mas SHEET 2 OF 4 TIER/YE}! SHEET 3 [IF A;

PATENTED mas m2 FOLDABLE LADDER CROSS'REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of my copending application under the same title, Ser. No. 847,099, filed Aug. 4, 1969, now U.S. Pat. No. 3,540,549.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to improvements in foldable ladders including a ladder structure having a foldable tripod supporting frame together with a novel brace arrangement permitting the ladder to be used in partially open position in confined areas and also including an improved design which adds to the convenient use of the ladder when weight forces thereon are concentrated near or at the top thereof.

2. Description of the Prior Art Foldable ladders, or step ladders as they are commonly referred to, are old and well known and include the conventional ladder structure having substantially parallel side pieces with connecting steps or rungs to which some form of a foldable brace means of lesser sturdiness than the side pieces is hingedly attached to the top portion of the respective side pieces of the ladder so that it can be swung out into ground engaging position. So far as is known, all such step ladders except the one disclosed in my copending application identified above, are designed so that the bottom ends of both step supporting side pieces are load bearing members and must engage the ground or supporting surface at all times to properly support the weight load. In addition, conventional step ladders generally include a pair of relatively closely spaced hinged brace legs that are swung out to support the side pieces in a well known manner. In some instances, the supporting brace legs are converged to form a single ground engaging means as exemplified in U.S. Pat. Nos. 4,451 and 46,105 but in addition to the ground engaging contact of the ladder side pieces and the single point of contact of the brace leg, there is also utilized additional side leg supports.

The use of a swingable or foldable support leg for a step ladder whether having a single ground engaging arrangement or a plural ground engaging arrangement does not overcome the difficulty of using the ladder in a rigid and stable condition when both of the ladders side rails must engage the ground or support in a weight bearing capacity. Conventional step ladders with a four point ground contact by the relatively closely spaced side rails and brace legs are quite susceptible to lateral tipping even when on a level surface and this susceptibility to tipping increases materially as the weight forces on the ladder are extended to its upper extremities. Also, the traditional step ladder has certain disadvantages when the ground level is uneven or sloping and while it is well known that shims or blocks are frequently placed under one of the side rails in such a situation, this does not correct the inherent instability of ladders of this type.

The present invention utilizes the principle of a tripod type supporting structure wherein three equally sturdy ground engaging support legs can be extended or folded out from an apex frame area to provide an extremely rigid and stable frame support. Utilizing the principle of a tripod-type frame, the present invention employs one of the tripod legs as one of the side pieces for the ladder component and provides the other side piece of the ladder component and with a lower hinged section which will permit it to engage level or slightly unlevel ground as a fourth support leg when the weight forces of the ladder are on any step connected to such lower section. Such arrangement, however, is only a matter of convenience in mounting on or demounting from the ladder as such fourth leg is not required to engage the ground as a bearing support since the structure of the ladder component is such that weight forces thereon are effectively transmitted to the tripod type frame structure to provide an extremely rigid and stable foldable ladder with increased safety and efficiency relative to LII other ladders of this type. With weight forces in steps not connected to such lower section, such section does not serve as a bearing support leg even though it may be in actual contact with the ground and all weight is carried! by the tripod frame.

It has been observed that step ladders are sometimes needed in restricted areas such as hall passageways, for example, where there may be insufficient room to fully extend the ladder to the locking position of the normal bracing. Accordingly, one of the improved features of the present ladder is to provide an adjustable bracing means which will rigidly hold the ladder in a partially extended position.

A further object of the present invention is to include a novel arrangement of a removable seat, foot rest attachment and a removable standard whereby the upper extremities of the ladder can be conveniently used in a safe manner that materially reduces the possibility of an occupant from falling or losing his balance at such point on the ladder.

Still another object of the present invention is to provide a plurality of various sized removable foot bearing members which can be utilized not only to maintain the ladder component in a suitable vertical plane on uneven ground but also to increase the bearing surface beneath the supporting leg so that the ladder can be efficiently used in soft or muddy surroundings.

SUMMARY This invention is directed to foldable ladders and the primary object herein is to materially improve the rigidity of the ladder supporting structure and to substantially increase the stability of the ladder and its safety while it is being used. For this purpose, this ladder incorporates a ladder component with a foldable tripod supporting structure.

One leg of the tripod frame is utilized as one of the side rails of the ladder. The other side rail of the ladder which is required for supporting the steps and which may be termed a fourth leg is not basically required to be a ground engaging support member but is designed with an upper and lower section hingedly attached in longitudinal alignment so that the lower section can be misaligned slightly with the upper section to facilitate the mounting on and dismounting from the ladder. For this purpose the lower section is normally capable of engaging level ground and by virtue of its hinged arrangement will generally engage uneven or unlevel ground that is not too pronounced. Thus, while the weight forces are effectively carried by the tripod frame for adequate safety and stability, the fourth leg, if in ground contact, serves as an additional support leg when one is mounting the ladder or demounting therefrom so long as weight forces are on steps connected to the lower section. As weight forces extend to steps not connected to the lower section, such forces are carried exclusively by the tripod frame whether or not the fourth leg is in ground contact and will also be carried exclusively by such frame if for any reason the fourth leg is not in contact with the ground because of appropriate bracing cooperation between such fourth leg and one of the main supporting legs. Thus, with the weight forces on the ladder always adequately distributed amongst three widely spaced tripod legs, the disadvantages of concentrating weight forces on the normally relatively closely spaced ladder side rails and brace legs in ordinary step ladders is eliminated and the ladder becomes a highly stable and safe item for use.

Because of the stableness of the tripod-type frame support, weight forces can be safely concentrated at the upper portion and even on the top plate of the ladder without danger of any tilting or twisting. In this regard, I have provided a novel removable standard vertically extending from the top plate that can be grasped by a person standing on the top plate to steady his balance. In addition, a suitable removable seat arranged relative to the top plate and a removable foot rest device is provided so that one using the ladder can conveniently sit on the top plate in safety as, for example, when cleaning or repairing windows or the like.

Step ladders are normally opened or extended to a fixed position usually defined by the operation of a suitable foldable brace. However, if the ladder is to be used in a restricted area not allowing the full extended opening of the ladder, the normal type bracing is ineffective since it cannot be extended to a locking position and the ladder is extremely unstable and relatively unsafe. In this regard, the present ladder includes an auxiliary adjustable brace device whereby the ladder can be opened and extended to selective adjustable positions so as to be usable in restricted areas in a manner in which its stability is assured. This ladder is also provided with removable bearing feet which provide a suitable means for maintaining the ladder component in an appropriate vertical position on uneven ground or a slope and which also makes possible the efficient use of this ladder in soft or muddy ground.

The objects of this invention together with details of the operation outlined and the advantages of the same will be more fully described and developed in relation to the more detailed description of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of this new ladder in folded position,

FIG 2 is a perspective view of this ladder in open or extended position ready for use and showing a removable standard or handle to steady ones balance when standing on the top plate,

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2 showing the hinged joint of one of the ladders side pieces,

FIG. 4 is a view of the underside of the bottom step taken from the line 44 of FIG. 2,

FIG. 5 is a perspective view taken from the line 5-5 of FIG. I to illustrate in solid and broken lines the respective closed and open position of one of the leg braces,

FIG. 6 is a side elevational view of the ladder shown in FIG. 2 and illustrating the use of supplementary bracing for adjusting the extended position of this ladder,

FIG. 7 is a perspective view of the lower portion of this ladder showing a second embodiment of adjusting the extended position thereof,

FIG. 8 is a fragmentary perspective view showing a modified form for one of the ladders supporting legs,

FIG. 9 is a perspective view of the upper portion of this ladder illustrating the removable convenience features which include a seat, an umbrella, and a foot rest,

FIG. 10 is a fragmentary perspective view of the ground engaging portion of the support legs and illustrating the use of removable bearing feet designed to keep the ladder in a proper plane on uneven ground,

FIG. 11 is a perspective view similar to FIG. 10 but showing the bearing feet inverted for use in soft, wet or muddy ground,

FIG. I2 is a perspective view showing the stacking arrangement for storage of the bearing feet in FIGS. 10 and 11, and

FIG. 13 is a perspective view of the foot rest shown mounted in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention incorporates the novel principle of a foldable tripod-type supporting frame for a step ladder as disclosed in my copending application described above and provides several improved features which materially add to the efficiency and convenience of use of this ladder as will appear as this description proceeds.

Referring to the drawings, this new ladder is designated generally by the numeral 14 as best seen in FIGS. 1, 2 and 6. The ladder component of this invention is designated generally by the numeral I6 and while it has the appearance of a conventional ladder structure, it includes certain novel features for purposes herein as will become apparent. The ladder component includes the spaced complementary side pieces I8 and of like length secured in the usual ladder relationship by a plurality of spaced steps or rungs 22 but with the top step being somewhat larger than the other steps so as to extend toward the user slightly further from said side pieces I8 and 20 than said other steps as can be seen in FIG. 6. It will be un' derstood that side pieces I8 and 20 may be parallel to each other or preferably they may be arranged to be somewhat further apart at the bottom than at the top as shown. Thus far described it will be appreciated that the ladder component has the conventional and traditional ladder structure and appearance. With reference, however, to ladder side piece 20, I have provided a hinge joint 24 at a point just above the plane of the second step 22 from the bottom so that in effect, side piece 20 comprises the two longitudinally aligned upper section 26 and lower section 28 as best seen in FIGS 2 and 3. The opposed ends of side piece sections 26 and 28 are provided with suitable respective hinge plates 30 and 32 pivotally secured by pins 34. A suitable spring means 36 (FIG. 3) is disposed within the confines of hinge plates 30 and 32 so as to project longitudinally into the opposed ends of side piece sections 26 and 28. By this arrangement, spring 36 acts to normally maintain side piece sections 26 and 28 in longitudinal alignment but will yield to permit the lower section 28 to pivot or bend slightly out of alignment with the upper section 26 either toward the rear or front side of ladder component 16 under circumstances as will be referred to later. To accommodate such pivoting of section 28 relative to all steps 22 attached thereto which as shown are the lower two steps 22, such steps are slidably connected to side piece 18 as shown in FIG. 4. In this regard, the steps 22 attached to section 28 carry on their underside a suitably secured elongated pin or rod 38 which at one end engages the outside of side piece section 28 by a suitable nut 40 and extends to and slidably through side piece 18. Preferably the inner surface of side piece I8 relative to pin 38 is provided with a suitable apertured bearing plate 42 and an enlarged collar 44 on pin 38 intermediate legs 18 and 20 slightly extends beyond the extremity of steps 22 adjacent side piece 18 so that the normal position of such steps as seen in FIG 4 leaves one edge of the lower two steps slightly spaced from side piece 18 to allow for the slight turning effect that results in the lower two rungs 22 when side piece section is hinged or pivoted as will appear. A cap 45 on pin 38 exteriorally of leg 18 serves as a stop to prevent the complete withdrawal of pin 38 from leg I8 during any hinged action between leg sections 26 and 28.

Ladder component 16 is supported basically and primarily by my improved foldable tripod-type support for which ladder side piece 18 serves as one of the main supporting legs with the other two basic support legs being legs 46 and 48. Leg 46 is preferably shorter in length than leg 18 and the upper end of leg 46 is pivotally secured to leg I8 at a point approximating the top surface level of the uppermost step 22 to form an apex area. While such pivot connection may be in any suitable form, I have preferably embraced leg 18 with a rigid strap 50 having free ends projecting rearwardly of leg 18 and between which leg 46 is pivotally secured by a pin 52. Strap 50 is also utilized to secure a vertically disposed standard 54 extending upwardly to the same plane as the top of leg 18 for supporting a top plate 56 that will later be referred to in more detail. A hinged brace means 58 connects legs 18 and 46 and permits leg 46 to be swung outwardly on pivot pin 52 to a predetermined position whereby brace 58 has an over the center locking component in a well-known manner.

Leg 20 is provided with a rigid strap 60 similar to strap 50 and on the same plane and also includes a vertical standard 62 similar to 54 to which the top plate 56 is suitably secured. It should be pointed out that top plate 56 is a relatively large rectangular platfonn and is adequately supported by the top of legs 18 and 20 and the tops of the standards 54 and 62. Such top plate is provided with an elongated slot 64 having one end in that portion of plate 56 above leg 20 and extending from such end in a curved path toward but not to the edge of such plate over legs 18 and 46 to point 66 which is beyond the halfway point on plate 56 toward such legs.

Leg 48 is disposed so that its upper end extends upwardly through and is movable in slot 64 in the top plate 56 and such leg 48 is suitably pivotally secured to the back side of leg on substantially the same plane as pivot point 52 for leg 46 and preferably slightly below such plane. For this purpose a collar 68 is secured to side piece portion 26 below plate 60 and supports a pivot pin 70 extending through a bearing 72 on a plate 74 attached to leg 48. Pin 70 is secured by an appropriate nut 76. Thus far described, in the closed or folded position of leg 48 as shown in FIG. 1, the upper end of such leg is in the extreme end of slot 64 opposite to end 66 and such leg generally is in juxtaposition to leg 20. In the open or extended position of the ladder, as seen in FIG. 2, the upper end of leg 48 has moved in slot 64 to point 66 and the lower ground engaging end of such leg is extended. Since point 66 is past center and closer to the right edge of top plate 56 as viewed in FIG. 2, it will be appreciated that the bearing of leg 48 at point 66 is in cooperation with the apex area formed by the connection between legs I8 and 46 and the effect of the arrangement of legs I8, 46 and 48 as described is such that weight forces on the ladder component will be appropriately distributed between these three tripod support legs. In addition, under certain circumstances as will appear, the support of such weight forces on the ladder component 16 is augmented by leg 20. The relative size of top plate 56 and the top step 22 as described is such that weight forces thereon will be naturally concentrated on the areas closest to the user whereby such forces are directed through standards 54 and 62 to the apex area.

A foldable V-shaped brace arrangement for stabilizing legs 18, 46 and 48 in open position is provided by means of a brace member 78 comprising the respective diverging elongated arms 80 and 82 with arm 82 being pivotally connected by pin 84 near one end portion of arm 82 as best seen in FIG. 2. The end portion 86 of arm 80 projecting beyond the pivot pin 84 is slidably connected in an elongated slot 88 formed in a guide plate 90 that is suitably secured to approximately the longitudinal center portion of leg 48. The other end of arm 80 is pivotally attached to the lower end portion of leg 18 slightly above the bottom thereof by any suitable pivot means designated generally by the numeral 92 and the other end of arm 82 is similarly pivotally attached to the lower portion of leg 46 by any suitable pivot means designated generally by the numeral 94.

A rod member 96 is secured at one end to brace 78 adjacent the pivot point 84 and for purposes here may be suitably secured to brace component 80 near such pivot point. Rod 96 extends to and connects with brace member 58 and serves to facilitate the opening and closing of leg 48 since by spreading apart legs I8 and I4, rod 96 is tilted with the movement of brace 58 and acts against brace 78 to urge it to open position. Conversely, by the closing of legs 18 and 46, the movement of rod 96 therewith correspondingly moves leg 48 to closed positlon. With ladder I4 in closed position as seen in FIG. I, end portion 86 of brace arm 80 will be at the upper extremity of slot 88 in plate 90 with brace arm 82 folded into juxtaposition with brace arm 80 and legs 48 and 46 will have moved into close parallel alignment with legs 20 and 18. In this position, a block means 98 is provided on the back side of the lower end of leg 20 against which leg 48 will abut to provide a stable bearing point for the bottom of leg 48 and thus add to the stability of this ladder in situations where it is used as a regular ladder as distinguished from a step ladder.

Leg 48 and brace 78 as described are illustrated as being made of board material but may, if desired, be of tubular material as seen in FIG. 8 where corresponding parts are given like numerals primed. Thus the arrangement and purpose of leg 48' and 78 and the brace 80' and 82 is the same as described for the corresponding parts in FIG. 2 and by reason of leg 48' being tubular, the function of the guide plate 90 in FIG. 2 is accomplished by providing the spaced stops I85 and I86 on leg 48. Slidable upon leg 48 intermediate stops I85 and I86 is a collar or sleeve 188 to which the respective arms 88 and 82' of brace 78 are suitably pivotally attached as shown. The rod 96 in FIG. 8 serves the same purpose as the corresponding rod 96 in FIG. 2.

Thus far described, it will be appreciated that if weight forces are placed on steps 22 of the ladder component I6 when the tripod frame is opened and when leg 20 was not in engagement with any ground support there would be a lateral twisting of ladder component I6 toward the brace member 78 and this would, of course, make the ladder structure unsatisfactory for use under such conditions. Accordingly, this problem is overcome by suitably transferring weight forces on the ladder directed against leg 20 to brace 78 as follows.

On the rear side of ladder side piece 20 and at the lower portion of the upper side piece portion 26 just above the hinge point 24 there is hingedly secured a suitable brace member I00 as best seen in FIGS. 2 and 5. Brace I00 is designed so that in the open or extended position of the ladder it projects rearwardly from leg section 26 as shown in the broken lines of FIG. 5 and in the closed position of the ladder component, it is rotated for compactness so as to abut the rear edge of an adjacent step 22 as seen in the solid lines of FIG. 5. A rod 102 is loosely connected at one end I04 to the unhinged portion of brace I00 and the other end 106 of rod I82 is slidable longitudinally of the rear edge of the adjacent step 22 in a suitable track means 108 secured to such step and in which track means there is provided a notch IIO. Thus when the ladder I4 is moved to open position, brace 100 can be manually moved from the solid line to dotted line position of FIG. 5 with end 106 of rod I02 sliding in track I08 until it seats in notch 1I0. To move brace I00 back to its closed position, it is only necessary to manually disengage rod end I06 from notch 110 and manually return brace 100 to its dotted line position of FIG. 5.

With the ladder 14 in open position as seen in FIG. 2 and with brace 100 in its open position as shown, such brace will bear against arm of the Vrbrace 78 at a point relatively close to but slightly below the pivot point 84 of brace 78. By this arrangement, the weight forces on any step of this ladder which would normally require the support of ladder side piece 20 are transmitted through brace and brace 78 to leg 48 so that the weight forces on the ladder are appropriately distributed for support between the tripod frame formed by legs 18, 46 and 48 to provide a highly stable support which eliminates the dangers of lateral twisting and tipping commonly found in ordinary step ladders.

With this ladder in open position as seen in FIG. 2, it will be appreciated that legs 18 and 46 extend in opposite directions but in the same plane and that leg 48 forms a substantially right angle position relative to the other legs. This permits the side of the ladder represented by legs 18 and 46 to be placed substantially flush against a building, for example, if work on such building requires the use of a ladder. In this regard, the arrangement and purposes of the brace 100 as described serves not only to transmit any weight load on leg 20 to leg 48 but also to maintain the ladder component 16 in a properly oriented position and plane for normal use.

Under normal circumstances on substantially level ground, leg 20 will be a ground engaging leg and in such an environment when weight forces are on any step 22 connected to the lower section 28, such leg will also be a fourth support leg on this ladder. The same result is obtained in situations where there is an unevenness or unlevelness in the ground of relatively small proportions where the hinge point 24 permits a small misalignment of the lower leg section 28 either forwardly or rearwardly of the upper section 26 so that the bottom of such leg section 28 can be moved into ground engagement. In the event of such misalignment, it will be appreciated that there would be a twisting of the steps 22 attached to section 28 relative to their association with leg I8 and accordingly, I have provided the arrangement previously described and illustrated in FIG. 4 wherein such bottom two steps are permitted to rotate slightly relative to leg 18 and may also slide slightly laterally relative thereto by reason of the arrangement of rod 38 as described.

The use of four ground support legs under the circumstances described has the main advantage of appearance of a conventional ladder when being mounted or dismounted and in the event that unevenness of the ground support is too great for leg to contact the same by misalignment with section 26 as described, weight forces on any step are adequately supported by legs 18, 46 and 48 because of the arrangement of braces 78 and 100 and when such weight forces are on any step not connected to the lower section 28, only the tripod frame legs 18, 46 and 48 are support members even though leg 20 may be physically touching the ground. It will thus be understood that the stability of this ladder is in no wise affected in the event that the bottom of leg 20 is out of engagement with the ground and that the contact of leg 20 with the ground under circumstances described is primarily a desirable effect for the user in the mounting and dismounting of the ladder.

The brace means 58 previously described is a common expedient on step ladders and by its well known over the center locking operation normally permits the extension or opening of such ladders to a predetermined point. However, it has been found that there are many situations where the use of a step ladder would be convenient yet because of certain restrictions in the area where the ladder is to be placed such as narrow hallways or the like, such ladder cannot be fully opened. To use an ordinary step ladder in such a situation would be highly dangerous in that the corresponding brace 58 could not be extended and locked. Thus, to make this step ladder safely usable in a restricted area, I have provided an auxiliary extension brace member 112 as best seen in FIG. 6. While brace 112 may be provided in a variety of forms, I have preferably used an extensible link device similar to a carpenter's foldable ruler with one end pivotally attached to leg 18 and normally held there in folded position by a suitable clip 114 as seen in FIG. 1. The outermost link of brace 112 is provided with a plurality of space notches 116 and when it is desired to use this ladder in a restricted area where brace 58 can be only partially opened as seen in FIGS. 2, legs 46 and 18 can be partially extended with brace 112 being engaged in an appropriate notch on a suitable stud 118 on leg 46 whereby it will be appreciated that brace 112 securely locks leg 18 and 46 against accidental folding the same as accomplished by brace 58 when it is normally used in its fully extended position. Also, since legs 18 and 46 are connected to leg 48 by brace 78 so that any movement of leg 48 is simultaneous with any movement of leg 46, the locking of leg 46 by brace 112 as described effectively locks leg 48 and thus as seen by the relationship of the solid and broken line position of leg 46 in FIG. 6, it will be understood that brace 112 makes possible the effective and safe use of this ladder in a relatively restricted ground area.

Another form of effectively bracing this ladder in open position and particularly in a restricted open position is illustrated in FIG. 7 where I have shown a triangular brace member 120 that is detachably secured to the basic tripod legs 18, 46 and 48. Brace 120 includes three rigid tubes or pipes 122, 124 and 126 strung on a suitable rope or cable 128 in a triangular form as seen in FIG. 7. At each point of the triangle, the rope or cable is formed into a respective loop 130 that is adapted to embrace the respective lower portions of each leg 18, 46 and 48 and to preferably be seated in a notch 132 formed on the exterior edge of each leg, such notches being best illustrated in FIG. 2. The overall size of brace 120 can be predetermined to provide any desired extension capacity of the tripod frame which may be less than that normally permitted by brace 58 and thus by partially extending such ladder and engaging brace 120 as shown, it will be appreciated that this ladder can be used in a safe manner even though brace 58 is ineffective. The rigidity of the pipe sections 122, 124 and 126 assure that brace 120 cannot be accidentally collapsed.

A paint bucket shelf 134 as seen in FIG. 2 is provided as a matter of convenience but the details thereof are not shown since no invention is claimed in such shelf per se and its manner of use and construction is well known in relation to step ladders.

With reference now to FIGS. 10-12, I have shown my new ladder foot member designated generally by the numeral 136 and which is adapted to serve as a levelling means on rough or uneven ground and also to serve as a bearing foot for making this ladder safely usable in wet or muddy surroundings. Foot 136 is basically a triangular boxlike member having a top 138, relatively deep sides 140 and three outwardly sloping legs 142. The top 138 is surrounded by an upstanding lip 144 and one of the legs as represented by the leg 142 at the left side of FIG. 10 is designated as the downhill leg and will be disposed on the downhill side relative to a slope 146 on which it may be used and in the construction of foot 136, with top 138 on a level plane, the plane of the two legs other than the downhill leg will be progressively higher. The downhill leg is preferably provided with a point or projection 148 for insertion into the ground and thus this foot 136 having in effect a sloping bottom plane can be disposed on the slope 146 and still present the level top surface 138 on which the bottom of one of the ladder legs can be placed. The surrounding lip 144 serves as a stop means against any accidental slipping of the ladder leg from top 138.

The reason for using one or more feet 136 is only for the purpose of orienting the ladder component 16 in a proper plane for convenient use. The tripod frame structure of ladder 14 will provide a rigid and stable support even on unlevel ground but if the unevenness is of any great extent, it can be appreciated that the inclination of the ladder component 16 relative to the ground would be somewhat awkward to use and, therefore, by using one or more of the feet 136, the proper alignment of ladder component 16 with the ground surface is easily obtained.

Preferably I provide a plurality of feet 136 of various appropriate sizes for use under different slope conditions and they can be conveniently nested as shown in FIG. 12 for purposes of storage and transportation.

By inverting the feet 136 as seen in FIG. 11, they serve the extremely useful purpose of providing an adequate bearing surface in wet or muddy terrain. In this regard the lip 144 penetrates the ground around the inverted top 138 and the relatively high depth of the sides 140 make it possible to keep the interior dry and clean so that the bottom of the ladder legs can be placed therein as shown.

Because of the inherent stability and sturdiness of ladder 14 with its tripod-type frame support as described, the upper portions of this ladder including the top plate 56 can be safely used without any danger of the ladder tipping, twisting or collapsing. Accordingly, to assist a user in maintaining his own balance while standing on the upper steps or even the top plate 56, I have provided the removable standard 150 as best seen in FIG. 2. Standard 150 is in essence an elongated pole 152 which can be extended downwardly through a hole 154 in top plate 56 and slidably journaled through a U-clamp 156 mounted to the inner side of leg 46 below the top step 22 as shown. A stop means 158 on pole 152 intermediate its ends is engageable with the top of the plate 56 and is incapable of passing through hole 154 so that standard 150 will extend upright from plate 56 any predetermined distance. Preferably, a handle member 160 is provided on the upper end of standard 150 to be grasped in the well-known manner. It will thus be appreciated that a person can safely stand on the top plate 56 and conveniently steady himself by grasping handle 160.

Since the relationship of ladder legs 18 and 46 is such that such ladder in open position may be placed in relatively close proximity to a building wall, I have provided certain other accessories to permit a user to conveniently use this ladder under circumstances such as washing windows, repairing windows and the like. Such accessories include a removable seat 162, a removable foot rest 164 and also a removable umbrella cover 166. The seat 162 is of a well-known type having a seat portion with a foldable back and no legs for which no invention is claimed and is of a type commonly used in boats or in athletic stadiums. The underside of the seat portion has a hook member (not shown) and in general seat 162 may be placed on top of the top plate 56 as seen in FIG. 9 whereby the usual underseat hook can be moved into engagement with the slot 168 on top plate 56. Such an arrangement provides a convenient means of providing a seat and back rest on the top of the ladder if the user prefers not to stand on the top plate. To further facilitate the use of seat 162, I have provided a removable foot rest 164 as best seen in FIG. 13. Foot rest 164 comprises an elongated board 170 having a respective foot tread 172 on each respective end portion. Foot rest 164 is designed to be placed on the second from the top step 22 against the inner side of legs 18 and 46 as seen in FIG. 9 and for this purpose, a hole 174 in board 170 registers with the U- clamp 156 so that with board 170 abutted against the inner side of legs 18 and 46, bolt 156 will project through hole 174. A stop or plug 176 secured to board 170 by a chain 178 so it will not become lost is inserted through U-clamp 156 to keep the foot rest 164 in engagement with leg 46. On the rung 22 on which board 170 rests there is a suitable stop 180 permanently fixed on the rung so that with the board inserted between such stop and leg 18 together with the locking means at U-clamp 156, foot rest 164 is suitably mounted for the convenient use of one using the seat 162. It will be understood that the length of board 170 is sufficient that the treads 172 are disposed at opposite sides and below seat 162 and extend outwardly relative to the corresponding side of the ladder so that a person sitting on seat 162 or top plate 56 can conveniently rest his feet on treads 172 and even stand on the same if he desires.

The umbrella 166 may be of any suitable type such as the well-known beach umbrella and the standard therefore 182 can be inserted through hole 154 in the top plate 56 and suitably anchored in a suitable U-bolt clamp 184 on board member 170. It will also be appreciated that the umbrella 166 can be used independently of the seat 162 and foot rest 164 and may be substituted in place of the standard 150 previously described.

Accordingly, from all of the foregoing, it is thought that the construction and use of this ladder will be understood and its several advantages appreciated.

lclaim:

l. A foldable ladder structure, comprising:

first and second spaced elongated side pieces having respective upper and lower ends and with a plurality of longitudinally spaced step members disposed intermediate said side pieces and secured thereto to form a ladder component,

said first side piece serving also as a first ground engaging support leg of a three-legged tripod frame ladder support,

a second elongated ground engaging support leg having an upper and lower end and pivotally secured at its upper end to the upper end portion of said first leg to form an apex,

a third elongated ground engaging support leg having an upper and lower end and pivotally secured near its upper end to the upper end portion of said second side piece so that when the lower end of said third leg is moved outwardly, the upper end thereof is moved toward and into cooperation with said apex,

movable brace means connected to said first, second and third legs for cooperation therewith when said legs are selectively extended into a tripod shape and returned to a folded position,

said second side piece comprising;

a respective upper and lower section in longitudinal alignment,

hinged means connecting opposed ends of said upper and lower sections whereby said lower section is capable of being moved out of longitudinal alignment with said upper section,

yielding means operatively associated with the opposed ends of said upper and lower sections to normally hold said lower section in longitudinal alignment with said upper section,

means on said upper section engaging said brace means for transmitting to said third leg any weight forces on any step member bearing against said second side piece,

said lower section when in alignment with said upper section being normally in engagement with a level ground support and on a relatively slightly unlevel support where said lower section does not normally engage said support movable slightly out of alignment with said upper section to engage said support, and

said lower section when in engagement with said support serving as a fourth support leg only so long as weight forces are applied to step members connected to said section.

2. A ladder structure as defined in claim 1 including:

said first, second and third legs by their tripod relationship and the cooperative association of said third leg with said second side piece serving to support all weight forces at any point on said ladder structure when said second side piece is out of engagement with a ground support, and

when weight forces are on said ladder structure above the hinged means of said second side piece, said first, second and third legs serving to support all of said weight forces both when said lower section is in engagement with a ground support and when it is out of engagement with a ground support.

3, A ladder structure as defined in claim 1 including:

means on all step members intermediate said lower section and said first side piece for movably connecting said step members to said first side piece to accommodate any relative movement therebetween when said lower section is moved out of longitudinal alignment with said upper section.

4. A ladder structure as defined in claim 1 including:

a brace member secured to said first leg and adapted at one end to be releasably attached to said second leg,

brace engagement means on said second leg, and

adjustable means on said one end of said brace member for selective releasable attachment to said brace engagement means whereby said second leg can be locked in selective positions of movement relative to said first leg and said movable brace means being connected to said first, second and third legs, said third leg is also held in a selective position against movement relative to said first and second legs.

5. A ladder structure as defined in claim 1 including:

a foldable brace connected to said first and second legs,

a rod member connected at respective ends to said respective movable and foldable braces, and

the movement of said first and second legs away from and towards each other with the resulting unfolding and folding of said foldable brace acting to effect a tilting of said rod member whereby said movable brace and said third leg are simultaneously moved to respective open and closed positions.

6. A ladder structure as defined in claim 1 including:

a triangular brace, and

respective means on each point of said brace for releasable engagement with said respective first, and second third legs when said legs are extended to form a tripod-type support.

7. A ladder structure as defined in claim 1 including:

said first and second legs when in extended position relative to each other being in the same plane, and

said third leg when extended being in a plane perpendicular to that of said first and second legs.

8. A ladder structure as defined in claim 1 including:

an elongated standard, and

means on one of said legs for releasably supporting one end of said standard so that the other end extends upwardly where it can be manually grasped for support by a person using the upper portion of said ladder.

9. A ladder structure as defined in claim 8 including a foldable umbrella on said other end of said standard.

10. A ladder structure as defined in claim 1 including the combination therewith of:

a bearing foot having a top, a plurality of sides and a plurality of ground engaging legs,

with said top on a level plane, said ground engaging legs being disposed on respective different planes of inclination to define one of said legs as a downhill leg, and

said bearing foot serving as a leveling means for said ladder component on a sloping support by positioning said downhill leg at the lower level of said support relative to the contact therewith by said other legs whereby said top is level and adapted to be engaged by one of said first, second and third legs of said ladder structure.

11. A ladder structure as defined in claim including:

said bearing foot adapted to be inverted for use in soft or wet ground whereby said top serves as a ground engaging bearing support, and

the lower end of one of said first, second and third legs of said ladder structure being supported on said inverted top within the confines of the surrounding sides of said bearing foot.

12, A ladder structure as defined in claim 1 including:

a top plate secured across the upper ends of said side pieces and being provided with an elongated slot, and

the upper end of said third leg being normally disposed in one end of said slot when said ladder is in folded position and moving to the other end of said slot when said ladder is extended.

13. A ladder structure as defined in claim 12 including:

a foot rest member for releasable attachment to said ladder structure, comprising:

an elongated horizontal support,

a horizontal foot tread on each end of said support, and

means on said first and second leg spaced below said top plate for releasably engaging said support so that said foot treads project outwardly from said legs and can be engaged by the feet of a person sitting on said top plate.

14. In a step ladder having spaced side pieces with connecting steps to form a ladder component and a brace leg structure movably associated therewith for movement toward and away from said side pieces, the combination therewith of:

an adjustable lockable brace means operatively associated with one of said side pieces and said brace leg structure whereby said brace leg structure can be locked at selected varying positions of movement away from said side pieces, said brace means comprising:

a brace member secured to one of said side pieces and adapted at one end to be releasably attached to said brace leg structure,

brace engagement means on said brace leg structure, and

adjustable means on one end of said brace member for selective releasable attachment to said brace engagement means whereby said side pieces and said brace leg structure can be locked in selective positions of movement relative to each other.

15. A foldable ladder structure, comprising:

a tripod-type frame defining first, second and third ground engaging support legs each having an upper and lower end,

means connecting the respective upper ends of said first and second legs to define the apex of said frame and at least one of said legs being pivotally associated with said apex for movement away from and toward said other legs,

said first leg also serving as a side piece for a ladder component,

a second side piece having an upper and lower end and being in spaced relationship to said first leg with a plurality of spaced step members disposed intermediate said side pieces and secured thereto to form a ladder component,

movable brace means connected to said first, second and third legs for cooperation therewith when said frame is selectively extended into a tripod shape and returned to a folded position,

means on said second side piece intermediate the upper and lower ends thereof engaging said brace means for transmitting to said third leg any weight forces on any step member bearing against said second side piece,

the lower end of said second side piece capable of engaging a level or substantially level ground support, and

said second side piece with its lower end in engagement with a ground support serving as a fourth support leg only so long as weight forces are applied to step members connected thereto at a point below the point of cooperative engagement between said second side piece and said movable brace means.

16. A ladder structure as defined in claim 15 including:

said first, second and third legs by their tripod relationship and the cooperative association of said third leg with said second side piece serving to support all weight forces on any step member on said ladder structure when the lower end of said second side piece is out of engagement with a ground support.

17. A ladder structure as defined in claim 15 including:

said first, second and third legs by their tripod relationship and the cooperative association of said third leg with said second side piece serving to support all weight forces on any step member connected to said second side piece at a point above the point of cooperative engagement between said second side piece and said movable brace means both when the lower end of said second side piece is in engagement with a ground support and when it is out of engagement with a ground support. 

1. A foldable ladder structure, comprising: first and second spaced elongated side pieces having respective upper and lower ends and with a plurality of longitudinally spaced step members disposed intermediate said side pieces and secured thereto to form a ladder component, said first side piece serving also as a first ground engaging support leg of a three-legged tripod frame ladder support, a second elongated ground engaging support leg having an upper and lower end and pivotally secured at its upper end to the upper end portion of said first leg to form an apex, a third elongated ground engaging support leg having an upper and lower end and pivotally secured near its upper end to the upper end portion of said second side piece so that when the lower end of said third leg is moved outwardly, the upper end thereof is moved toward and into cooperation with said apex, movable brace means connected to said first, second and third legs for cooperation therewith when said legs are selectively extended into a tripod shape and returned to a folded position, said second side piece comprising: a respective upper and lower section in longitudinal alignment, hinged means connecting opposed ends of said upper and lower sections whereby said lower section is capable of being moved out of longitudinal alignment with said upper section, yielding means operatively associated with the opposed ends of said upper and lower sections to normally hold said lower section in longitudinal alignment with said upper section, means on said upper section engaging said brace means for transmitting to said third leg any weight forces on any step member bearing against said second side piece, said lower section when in alignment with said upper section being normally in engagement with a level ground support and on a relatively slightly unlevel support where said lower section does not normally engage said support movable slightly out of alignment with said upper section to engage said support, and said lower section when in engagement with said support serving as a fourth support leg only so long as weight forces are applied to step members connected to said section.
 2. A ladder structure as defined in claim 1 including: said first, second and third legs by their tripod relationship and the cooperative association of said third leg with said second side piece serving to support all weight forces at any point on said ladder structure when said second side piece is out of engagement with a ground support, and when weight forces are on said ladder structure above the hinged means of said second side piece, said first, second and third legs serving to support all of said weight forces both when said lower section is in engagement with a ground support and when it is out of engagement with a ground support.
 3. A ladder structure as defined in claim 1 including: means on all step members intermediate said lower section and said first side piece for movably connecting said step members to said first side piece to accommodate any relative movement therebetween when said lower section is moved out of longitudinal alignment with said upper section.
 4. A ladder structure as defined in claim 1 including: a brace member secured to said first leg and adapted at one end to be releasably attached to said second leg, brace engagement means on said second leg, and adjustable means on said one end of said brace member for selective releasable attachment to said brace engagement means whereby said second leg can be locked in selective positions of movement relative to said first leg and said movable brace means being connected to said first, second and third legs, said third leg is also held in a selective position against movement relative to said first and second legs.
 5. A ladder structure as defined in claim 1 including: a foldable brace connected to said first and second legs, a rod member connected at respective ends to said respective movable and foldable braces, and the movement of said first and second legs away from and towards each other with the resulting unfolding and folding of said foldable brace acting to effect a tilting of said rod member whereby said movable brace and said third leg are simultaneously moved to respective open and closed positions.
 6. A ladder structure as defined in claim 1 including: a triangular brace, and respective means on each point of said brace for releasable engagement with said respective first, and second third legs when said legs are extended to form a tripod-type support.
 7. A ladder structure as defined in claim 1 including: said first and second legs when in extended position relative to each other being in the same plane, and said third leg when extended being in a plane perpendicular to that of said first and second legs.
 8. A ladder structure as defined in claim 1 including: an elongated standard, and means on one of said legs for releasably supporting one end of said standard so that the other end extends upwardly where it can be manually grasped for support by a person using the upper portion of said ladder.
 9. A ladder structure as defined in claim 8 including a foldable umbrella on said other end of said standard.
 10. A ladder structure as defined in claim 1 including the combination therewith of: a bearing foot having a top, a plurality of sides and a plurality of ground engaging legs, with said top on a level plane, said ground engaging legs being disposed on respective different planes of inclination to define one of said legs as a downhill leg, and said bearing foot serving as a leveling means for said ladder component on a sloping support by positioning said downhill leg at the lower level of said support relative to the contact therewith by said other legs whereby said top is level and adapted to be engaged by one of said first, second and third legs of said ladder structure.
 11. A ladder structure as defined in claim 10 including: said bearing foot adapted to be inverted for use in soft or wet ground whereby said top serves as a ground engaging bearing support, and the lower end of one of said first, second and third legs of said ladder structure being supported on said inverted top within the confines of the surrounding sides of said bearing foot.
 12. A ladder structure as defined in claim 1 including: a top plate secured across the upper ends of said side pieces and being provided with an elongated slot, and the upper end of said third leg being normally disposed in one end of said slot when said ladder is in folded position and moving to the other end of said slot when said ladder is extended.
 13. A ladder structure as defined in claim 12 including: a foot rest member for releasable attachment to said ladder structure, comprising: an elongated horizontal support, a horizontal foot tread on each end of said support, and means on said first and second leg spaced below said top plate for releasably engaging said support so that said foot treads project outwardly from said legs and can be engaged by the feet of a person sitting on said top plate.
 14. In a step ladder having spaced side pieces with connecting steps to form a ladder component and a brace leg structure movably associated therewith for movement toward and away from said side pieces, the combination therewith of: an adjustable lockable brace means operatively associated with one of said side pieces and said brace leg structure whereby said brace leg structure can be locked at selected varying positions of movement away from said side pieces, said brace means comprising: a brace member secured to one of said side pieces and adapted at one end to be releasably attached to said brace leg structure, brace engagement means on said brace leg structure, and adjustable means on one end of said brace member for selective releasable attachment to said brace engagement means whereby said side pieces and said brace leg structure can be locked in selective positions of movement relative to each other.
 15. A foldable ladder structure, comprising: a tripod-type frame defining first, second and third ground engaging support legs each having an upper and lower end, means connecting the respective upper ends of said first and second legs to define the apex of said frame and at least one of said legs being pivotally associated with said apex for movement away from and toward said other legs, said first leg also serving as a side piece for a ladder component, a second side piece having an upper and lower end and being in spaced relationship to said first leg with a plurality of spaced step members disposed intermediate said side pieces and secured thereto to form a ladder component, movable brace means connected to said first, second and third legs for cooperation therewith when said frame is selectively extended into a tripod shape and returned to a folded position, means on said second side piece intermediate the upper and lower ends thereof engaging said brace means for transmitting to said third leg any weight forces on any step member Bearing against said second side piece, the lower end of said second side piece capable of engaging a level or substantially level ground support, and said second side piece with its lower end in engagement with a ground support serving as a fourth support leg only so long as weight forces are applied to step members connected thereto at a point below the point of cooperative engagement between said second side piece and said movable brace means.
 16. A ladder structure as defined in claim 15 including: said first, second and third legs by their tripod relationship and the cooperative association of said third leg with said second side piece serving to support all weight forces on any step member on said ladder structure when the lower end of said second side piece is out of engagement with a ground support.
 17. A ladder structure as defined in claim 15 including: said first, second and third legs by their tripod relationship and the cooperative association of said third leg with said second side piece serving to support all weight forces on any step member connected to said second side piece at a point above the point of cooperative engagement between said second side piece and said movable brace means both when the lower end of said second side piece is in engagement with a ground support and when it is out of engagement with a ground support. 